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lack of high-performance catalysts regardless of electrolyte pH. [7][8][9] Although optimizing the acidity of the electrolyte can tune the activity of a catalyst, designing the pseudo-pH-independent catalyst may make the water electrolyzers more affordable and safer for commercial H 2 production and home usage, respectively. [10,11] As one of the most renowned transitional metal dichalcogenides (TMDs), molybdenum disulfide (MoS 2 ) shows significant tuning potential for HER. [12][13][14][15][16][17] However, due to the inefficient cleavage of water molecules and sluggish H desorption, the activity of MoS 2 is unsatisfactory in overall pH values. [18][19][20][21][22] As reported by previous works, although the limited edge site with the unsaturated coordination is an active site for HER, especially in acidic media, the whole basal plane with the majority of atoms is immensely inert, the essence of the disappointing HER performance. [23][24][25] More specifically, the unsuitable orbital composition in the conduction band of MoS 2 , including S 3p x,y and Mo 4d z 2 , possesses an unfavorable electron-interaction with H atoms and water molecules on account of improper orbital orientation, rendering the basal plane of MoS 2 become inert for HER. [23,26] Several strategies, such as hetero-atom doping, [27][28][29][30][31] phase and interface tuning, [32,33] and defect engineering [34] have been employed to untangle the above drawback. For instance, Duan and co-workers synthesized the active basal plane of MoS 2 by replacing some Mo atoms with Co, which induces long-range ferromagnetic order to activate S atoms. [35] Moreover, Zheng and the colleagues prepared an active and stable catalyst via co-confining Se in the surface and Co in the inner layer of MoS 2 . [36] They proved that the activating effect of Co with the stabilizing effect of Se enables the formation of abundant active sites in the basal plane and the edges of MoS 2 . Previously, our research group fabricated carbon-induced MoS 2 via a controlled sulfurization of Mo 2 C. [26] Experimental and theoretical analyses revealed that carbon effectively altered the electronic and coordination structures of MoS 2 through emptying 2p orbitals perpendicular to the basal plane, enabling energetically favorable water adsorption and dissociation. Besides, Xiong et al. synthetized a bifunctional catalyst by doping Co atoms into the MoS 2 matrix. [37] They demonstrated that Co doping not only dramatically enhances HER performance but also induces superior MoS 2 represents a promising catalyst for the hydrogen evolution reaction (HER) in water splitting, but the inefficient catalytic activity in a pH-universal environment is an obstacle to developing practical applications. Boosting and balancing the water dissociation and hydrogen desorption kinetics is crucial in designing high-performance catalysts for the overall pH range. Herein, it is experimentally demonstrated that cobalt single-atom doping can effectively construct a reactive CoMoS micro-environment on the basal...

The current study was aimed at developing a package of “model + algorithm” for the design of resin in pulp (RIP) and carbon in pulp (CIP) processes of gold, uranium, and base metals. For this purpose, we first formulated a double‐resistance model for irreversible adsorption (accompanied by chemical reaction) in CSTRs, and modified the McKay et al. semi‐analytical model for reversible uptake in a similar system. We then devised two algorithms for the design and optimization of reversible and irreversible RIP and CIP cascades. The developed algorithms were applied on the extraction of copper, uranium, and gold. The packages are able to specify the optimum number of stages, reactor volume (V), resin flow rate (m.), and resin hold up (φs). This shows an evident advantage over the McCabe‐Thiele method, whose only result is the number of stages. The new methods have only two adjustable parameters of diffusivity (Deff) and liquid film coefficient (k), whose determination can be carried out through simple batch experiments. As an additional work, this study also presents a method for mathematical troubleshooting for the Mc Kay et al. model.

Recently, single-atom catalysts (SACs) have been found to be one of the promising candidates for oxygen electrocatalysis in rechargeable lithium-oxygen batteries (LOBs), owing to their high oxygen electrocatalytic activity and high stability originated from their unique coordination environments and electronic properties. As a new type of catalysts for LOBs, the advancements have never been reviewed and discussed comprehensively. Herein, the breakthroughs in the design of various types of SACs as the cathode catalysts for LOBs are summarized, including Co-based, Ru-based, and other types of SACs. Moreover, considerable emphasis is placed on the correlations between the structural feature of the SAC active sites and the electrocatalytic performance of LOBs. Finally, perspective and challenges of SACs for practical LOBs are also provided. This review could provide an intensive understanding of SACs for designing efficient oxygen electrocatalysis and offers a useful guideline for the development of SACs in the field of LOBs.

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Although it is well acknowledged that regulating the adsorption behavior of oxygen-containing intermediates can prompt the reaction kinetics of lithium–oxygen batteries, its implementation still suffers from lacking a practical strategy. The amorphization strategy has great potential for custom-tuning surface engineering due to the induced atomic disorder possessing unique electronic structures and abundant defect sites. In this work, amorphous NiCo2O4 nanosheets (a-NiCo2O4 NSs) are reported for high-performance lithium–oxygen batteries by modulating the electron density around metal sites. The Li–O2 batteries with a-NiCo2O4 NSs deliver an overpotential as low as 0.74 V with an ultralong lifetime of over 1000 h. Theoretical calculations reveal that the enhanced binding energy of the LiO2 intermediate is stemmed from d-band center upshifting, mediated by atomic disordering, which consequently yields low oxygen evolution-reaction and oxygen-reduction-reaction overpotentials. More importantly, the amorphization strategy can be utilized as a general approach toward other materials, such as cobalt oxide and nickel oxide.